Simulation of the Steering System Power Demand during the Concept Phase Focusing on Tire Modelling at Standstill
- 9 November 2021
- journal article
- research article
- Published by SAE International in SAE International Journal of Passenger Cars - Mechanical Systems
- Vol. 14 (3), 193-214
- https://doi.org/10.4271/06-14-03-0012
Abstract
Estimating the power demand of a steering system is one of the main tasks during steering system development in the concept phase of a vehicle development process. Most critical for typical axle kinematics are parking maneuvers with simultaneously high rack forces and velocities. Therefore, the focus of the article is a tire model for standstill, which can be parametrized without measurements, only having tire dimensions and conditions (inflation pressure and wheel load) as input. Combined with a double-track model, a vehicle model is developed, which is able to predict the rack force and is fully applicable during the concept phase. The article demonstrates quantitatively that the tie rod forces, and thereby especially the tire bore torque, cause the largest fraction of the power demand at the rack. For this reason, the prediction of the bore torque is investigated in detail, whereby basic approaches from the literature are analyzed and enhanced. Furthermore, an approach is derived for considering the influence of horizontal forces in the tire contact patch on the bore torque. The development of the tire model is supported by a tire data basis with approximately 900 measured tire configurations. Finally, two test vehicles are used to validate the vehicle model successfully.Keywords
This publication has 2 references indexed in Scilit:
- Modeling and friction estimation for automotive steering torque at very low speedsVehicle System Dynamics, 2020
- Tire Model for Turn Slip PropertiesSAE International Journal of Commercial Vehicles, 2013